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Long-Term Debt (Narrative) (Details) |  |  | 6 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Jun. 30, 2016 USD ($) | Mar. 10, 2016 USD ($) | Jun. 30, 2016 USD ($) | Dec. 31, 2013 USD ($) | Dec. 31, 2015 USD ($) | Aug. 14, 2013 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |
Senior notes |  |  |  |  |  | $ 500,000,000
Cash dividend to former parent |  |  |  | $ 650,000,000 |  |
Fixed charge coverage ratio | 0.70 |  | 0.70 |  |  |
Fixed charge coverage ratio threshold, percentage of aggregate facility commitments and borrowing base | 17.50% |  | 17.50% |  |  |
Fixed charge coverage ratio threshold, amount of aggregate facility commitments and borrowing base |  |  | $ 70,000,000 |  |  |
Dividend restrictions |  |  | After giving effect to the applicable restrictions on certain payments, which could include dividends under the credit agreement (which restrictions are only applicable when availability under the credit agreement does not exceed the greater of 25% of the lesser of the revolving commitments and the borrowing base and $100 million (and if availability under the credit agreement does not exceed the greater of 40% of the lesser of the revolving commitments and the borrowing base and $100 million, then our fixed charge coverage ratio must be at least 1.0 to 1.0) and the indenture, and subject to compliance with applicable law. As of December 31, 2015, the Company had a shortfall of approximately $245.7 million of its net income and retained earnings subject to such restrictions before the fixed charge ratio would exceed 1.0 to 1.0 . |  |  |
Net income and retained earnings free of restrictions, excess (deficit) of |  |  |  |  | $ (245,700,000) |
Minimum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Fixed charge coverage ratio | 1.0 |  | 1.0 |  | 1.0 |
Period for fixed charge coverage ratio threshold (in days) |  |  | 3 days |  |  |
Dividend restriction threshold as a percentage of revolving commitments and borrowing base | 25.00% |  | 25.00% |  |  |
Dividend restriction threshold as amount of availability | $ 100,000,000 |  | $ 100,000,000 |  |  |
Dividend restrictions, fixed charge coverage ratio |  |  | 1.0 |  |  |
Maximum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Secured leverage ratio | 4.5 |  | 4.5 |  |  |
Dividend restriction threshold as a percentage of revolving commitments and borrowing base with consideration of fixed charge coverage ratio | 40.00% |  | 40.00% |  |  |
Dividend restriction threshold as amount of availability with consideration of fixed charge coverage ratio | $ 100,000,000 |  | $ 100,000,000 |  |  |
Federal Funds Rate |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 0.50% |  |  |
LIBOR |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 1.00% |  |  |
Interest period one (in months) |  |  | 1 month |  |  |
Interest period two (in months) |  |  | 2 months |  |  |
Interest period three (in months) |  |  | 3 months |  |  |
Interest period four (in months) |  |  | 6 months |  |  |
Cash |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Percentage of asset available to borrow against | 100.00% |  | 100.00% |  |  |
Credit Card Receivables |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Percentage of asset available to borrow against | 90.00% |  | 90.00% |  |  |
Investment Grade Accounts |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Percentage of asset available to borrow against | 90.00% |  | 90.00% |  |  |
Other Accounts |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Percentage of asset available to borrow against | 85.00% |  | 85.00% |  |  |
Midstream Refined Products Inventory |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Percentage of asset available to borrow against | 80.00% |  | 80.00% |  |  |
Refined Retail Products Inventory |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Percentage of asset available to borrow against | 75.00% |  | 75.00% |  |  |
Retail Merchandise Inventory |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Percentage of asset available to borrow against | 70.00% |  | 70.00% |  |  |
Percentage of net orderly liquidation value available to borrow against | 85.00% |  | 85.00% |  |  |
Asset-Based Loan Facility |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity | $ 450,000,000 |  | $ 450,000,000 |  |  |
Outstanding debt | 0 |  | $ 0 |  |  |
Asset-Based Loan Facility | LIBOR | Minimum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 1.50% |  |  |
Asset-Based Loan Facility | LIBOR | Maximum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 2.00% |  |  |
Asset-Based Loan Facility | Alternative Base Rate | Minimum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 0.50% |  |  |
Asset-Based Loan Facility | Alternative Base Rate | Maximum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 1.00% |  |  |
Term Facility |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity | 200,000,000 |  | $ 200,000,000 |  |  |
Proceeds borrowed from credit facility |  | $ 200,000,000 |  |  |  |
Term (in years) |  |  | 4 years |  |  |
Quarterly amortization payment (percent) |  |  | 5.00% |  |  |
Quarterly amortization payment | 10,000,000 |  |  |  |  |
Term Facility | LIBOR | Minimum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 2.50% |  |  |
Term Facility | LIBOR | Maximum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 2.75% |  |  |
Term Facility | Alternative Base Rate | Minimum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 1.50% |  |  |
Term Facility | Alternative Base Rate | Maximum |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Spread over variable rate (percent) |  |  | 1.75% |  |  |
Incremental Facility |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity | 150,000,000 |  | $ 150,000,000 |  |  |
Letter Of Credit |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of credit facility, sublimit | $ 200,000,000 |  | $ 200,000,000 |  |  |
Senior Notes |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Interest rate (percent) | 6.00% |  | 6.00% |  |  | 6.00%

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